There is a display device that seals the periphery of a display functional layer such as a liquid crystal layer by arranging the display functional layer between a pair of substrates oppositely arranged. Japanese Patent Application Laid-Open No. 2014-26199 (Patent Document 1) discusses forming a slit serving as a region where there is no black matrix around a sealing material, and blocking water entering a display functional layer from an interface between the substrate and a black matrix.
A display device has a configuration in which a display functional layer such as a liquid crystal layer is formed between a pair of substrates, the substrates are adhesively fixed to each other with a sealing material in a sealing section around the display functional layer, so that the display functional layer is protected.
An organic film composed of an organic material such as resin is formed as a protective film and a light shielding film, for example, in substrates oppositely arranged. If the organic film is thus formed in the substrate, water easily enters the display functional layer via the inside of the organic film or an interface between the organic film and the substrate. When water enters the display functional layer, a constituent material of the display functional layer changes in quality, so that a display functional characteristic may change. That is, entrance of water into the display functional layer causes a decrease in display quality.
A method for suppressing entrance of water into the display functional layer includes a method for forming a slit in an organic film so as to surround the periphery of a display region. The slit formed in the organic film is formed by removing the organic film so as to be penetrated in a thickness direction. In this case, a distance of an entrance path of water increases, so that entrance of water can be reduced.
If the slit is formed in the organic film so as to surround the periphery of the display region, however, a function required for the organic film cannot be exhibited in a portion where the slit is formed. If the slit is formed in the organic film formed as a protective film of a circuit pattern, for example, the circuit pattern in a portion overlapping the slit is not protected. Alternatively, if the slit is formed in the organic film formed as a light shielding film, a light shielding member for suppressing leakage of light needs to be formed in a location other than the portion where the slit is formed so as to suppress leakage of light from a portion where the slit is formed.
When measures taken when the function required for the organic film is not exhibited are considered in the portion where the slit is formed, therefore, the area of a portion referred to as a so-called frame section or frame region serving as a non-display portion surrounding the periphery of the display region is difficult to reduce.